1. Field of Invention
This invention relates to the coupling of light-weight tubular structural members to an inexpensive and easy to fabricate quick connect spherical hub or node mechanism for the assembly of truss structures to be used as a component based, building kit for larger space frame structures.
2. Prior Art
Traditionally, space frame truss structures have been constructed from component kits comprised of nodal elements and struts, which fit together in a geometrically repeating pattern with the strut ends securely attached to the nodal elements to build large, multi-component structures. Alternatively, nodeless methods have been developed that utilize welding, riveting and flanging struts together. Using these methods, long distances can be spanned with relatively light weight materials, achieving a level of strength otherwise only possible by using heavier conventional beam construction methods. The resulting space frame structures are light weight, high strength, and relatively easy to build.
Space frame construction has been widely used for building commercial structures but not for residential structures. It is currently limited in application due to high component manufacturing costs and weight concerns. Typically, space frame nodal elements are made with forged and machined steel spherical hubs. A common strut member is screwed or locked into the facet receiving opening on the hub. These forged and machined hubs are not only heavy and expensive to make, but they typically are limited to at most twelve radial directions for connecting struts. Additionally, later modifications to the assembled space frame structure (either expansion or reduction) are either impossible or require significant structural disassembly prior to making changes.
If component based, space frame construction methods are to achieve their earlier anticipated wide scale use, the hubs and strut fastening mechanisms must become simpler, lighter, and less expensive to manufacture. Additionally, the ability to easily modify these structures will enhance their potential use.